Drug & supplement interaction

American Ivy + Chlorthalidone

Chlorthalidone brand names: Hygroton, Thalitone.

Moderate Interaction
The bottom line Moderate

American Ivy has a moderate interaction with Chlorthalidone. The berries of American ivy contain up to 2% oxalic acid, which can be toxic because it has the potential to cause kidney failure by precipitating solid calcium oxalate.

Read the full interaction report
SeverityModerate
LikelihoodUnlikely
EvidenceC
What do Severity, Likelihood & Evidence mean?
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Interaction report

American Ivy and Chlorthalidone

Here is the interaction we found between these two, with the evidence behind it.

Moderate

Thiazide Diuretics

Why this applies to Chlorthalidone

Chlorthalidone falls under Thiazide Diuretics — the group American Ivy interacts with.

The berries of American ivy contain up to 2% oxalic acid, which can be toxic because it has the potential to cause kidney failure by precipitating solid calcium oxalate. Thiazide diuretics are often prescribed to decrease urinary calcium levels and prevent the formation of calcium oxalate kidney stones. Consequently, the berries of American ivy and thiazide diuretics may have opposing effects in this context, as the diuretics work to lower urinary calcium levels while the oxalic acid in the berries could potentially increase the risk of kidney stone formation. It is important to note that medicinal supplements utilizing American ivy generally only make use of the bark, not the berries.
Severity Moderate Likelihood Unlikely Evidence C

Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans..

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the gist of this one. Chlorthalidone is a water pill that actually helps your kidneys hold onto calcium and lowers the calcium in your urine, which is one reason doctors use it to prevent calcium oxalate kidney stones. The concern with American Ivy is specific to its berries, which hold up to about 2% oxalic acid. That oxalic acid could push in the opposite direction by raising the risk of those same calcium oxalate stones.

This is a theoretical, low-likelihood concern, and most American Ivy supplements use the bark, not the toxic berries. Still, the berries are genuinely poisonous, so don't eat them. If you take Chlorthalidone and are curious about this plant, run it by your pharmacist or doctor first.

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

American Ivy Also Interacts With Other Medications

American Ivy has 55 moderate known drug interactions in our database — the Chlorthalidone one above is one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against American Ivy

Covers the 2,830 medications we’ve checked against American Ivy. Pick one to open its full report.

From our Q&A

Questions About American Ivy or Chlorthalidone

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers American Ivy or Chlorthalidone, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Chlorthalidone

This page covers American Ivy only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Chlorthalidone page lists 222 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), American Mistletoe (major), Dolomite (major) and Lithium (major).

By severity: 8 major · 190 moderate · 24 minor.

From our pharmacist’s overview on the Chlorthalidone page

“Chlorthalidone (Hygroton, Thalitone) lowers blood pressure by helping the kidneys shed salt and water, and that mechanism makes its supplement interactions worth genuine care. Most of the 222 ingredients on file either add to its blood-pressure-lowering effect or act as diuretics themselves, so pressure or potassium can fall further th…”

Reviewed by 2 · Jul 18, 2026

Open the Chlorthalidone interaction page

How much people look this up

Where American Ivy and Chlorthalidone Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement American Ivy
Steady interest

#1,172 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Chlorthalidone
Steady interest

#1,580 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Supplement

About American Ivy

What is American Ivy?

American Ivy
  • Digestive upset
  • To stimulate sweating
  • Traditional tonic use
  • Skin and swelling complaints (topical folk use)

American Ivy (Virginia creeper) is mainly an ornamental climbing vine with a long history of folk use for digestion and sweating, but there is very little human evidence to support any health benefit. Its berries contain oxalic acid and are considered poisonous, and the plant can irritate the skin. Because safety data is limited, talk with your pharmacist or doctor before using it.

Read the full American Ivy monograph & all interactions
Medication

About Chlorthalidone

What Is Chlorthalidone Used For?

Brand names: Hygroton, Thalitone

Chlorthalidone is used to treat high blood pressure (hypertension) in adults. Lowering blood pressure reduces the risk of serious cardiovascular events, especially strokes and heart attacks. It can be used alone or combined with other blood pressure medicines.

Chlorthalidone is also used as an add-on treatment for edema (fluid buildup) caused by heart failure, liver cirrhosis, and kidney conditions including nephrotic syndrome, acute glomerulonephritis, and chronic renal failure. Thalitone is additionally indicated for edema associated with heart failure, liver cirrhosis, and renal disease including nephrotic syndrome.

See full Chlorthalidone drug information
Keep checking

Other Drugs & American Ivy

Browse every other medication we’ve checked against American Ivy — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
55Moderate
0Minor
2,774No known interaction
Moderate

55 interactions

No interaction 2,774 drugs checked — show the list
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

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Pharmacist Counseling Corner

Taking American Ivy and Chlorthalidone Together: Common Questions

Can you take American Ivy with Chlorthalidone?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the American Ivy and Chlorthalidone interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Chlorthalidone and American Ivy?

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.